408/ 904 trans

Have to disagree with ya there. The A body has lots of rear overhang and makes an excellent racecar. Thats why if you go to any bracket race, you see more Dusters than Carter has liver pills.
I raced a 70 Duster for many years in various forms, the last few years with a 9 sec stroker smallblock.
I had 002/003 leafs and CE 3 way shocks on all 4 corners and the car would hook on ice with 28 by 10 bias ply DOT tires. Anywhere. Won races and went rounds with that car. It was better than the driver( me.. lol)
I find more posts from guys who have bought Cal tracs and put them on A bodies and cant get the car to stick than anything, over the years. I got my pinion angle set at 5 degrees down with the S/S springs, and let her rip.
A bodies make GREAT race cars, and Mopar S/S springs work outstanding well into the 9’s.... even on a small tire. Thats fact

My point is when you look at the thrust vector in the chassis its all wrong because of the instant center is well above the center of gravity of the car. This makes the car more sensitive to track conditions. As you pointed out more guys have problems with caltrac A bodies than any other suspension, thats the reason. The Chevy and Ford cars have 25+ inch long front spring segments (which puts the instant center in a far better location in the car) as opposed to the 20" Mopar, and thats why those car work well with Caltracs.
I'm looking at going back to SS type springs next year, I've had enough of the Caltrac KoolAid